The effect of hyperglycemia on extracellular levels of adenosine in the hypoxic rat cerebral cortex.
The levels of adenosine in rat cerebral cortical superfusates were studied in rats prior to, and after, the administration of saline or D-glucose (3 g/kg). Hypoxia-evoked increases in purine release were significantly attenuated after glucose administration. After glucose administration, the falls in arterial blood pressure, which normally accompany systemic hypoxia, were reduced. To ensure that this was not the reason for the decrease in adenosine release, blood was withdrawn from a second group of hyperglycemic rats so that the post-glucose hypoxia was equivalent to the original control. Adenosine release was still significantly attenuated. This decrease in the levels of adenosine, a cerebroprotective agent, in the cerebral cortical extracellular space, may be a contributing factor to the detrimental effects of hyperglycemia on recovery from cerebral ischemia.
Phillis
J W
JW
Department of Physiology, Wayne State University School of Medicine, Detroit, MI 48201.
Simpson
R E
RE
Walter
G A
GA
D000241:Adenosine / Q000378:metabolism*; D000818:Animals; D001794:Blood Pressure; D002540:Cerebral Cortex / Q000378:metabolism*; D005110:Extracellular Space / Q000378:metabolism; D006943:Hyperglycemia / Q000378:metabolism* / Q000503:physiopathology; D000860:Hypoxia / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values
D000241:Adenosine